1. Field of the Invention
The present invention relates to an aerated composition comprising an associative polymer and an anionic surfactant and to its use in particular for treating and/or cleansing human skin, including the scalp, nails and/or hair, in particular for caring for dry skin and/or dry lips, and for making up the skin.
2. Description of the Related Art
Users of skin care products are increasingly looking for products which are pleasant to use and which have a novel texture. Until now, cosmetic compositions have been generally provided in the form of solutions, gels or more or less fluid creams.
Creams are conventionally composed of an emulsion. Emulsions comprise an aqueous phase and an oily phase dispersed in one another. Oil-in-water (O/W) emulsions, the external phase of which is the aqueous phase, are more particularly desired because they contribute more freshness on application than water-in-oil (W/O) emulsions comprising an oily external phase. Their feel and their application seem to be less greasy than those of a W/O emulsion. In addition, they make possible a high level of moisturizing, which is particularly useful in caring for dry skin or lips.
In order to confer a novel texture on emulsions, attempts have been made to introduce a gas, generally air, therein in order to confer on them a light texture and to give them the appearance of a foam. This is what is known as expansion. The aerated emulsions obtained are appreciated for their lightness on application. Nevertheless, they exhibit the disadvantage of being relatively unstable because of their low relative density and thus of separating out after a certain storage time. The application CH-A-674,804 discloses stabilization of an aerated cosmetic cream comprising an inert gas or air by the addition of an aqueous solution of a protein of animal origin. However, the use of such proteins is avoided in cosmetics.
Furthermore, the application JP-A-56/079613 discloses stable aerated surfactant-free compositions comprising from 5 to 20% of waxes, preferably waxes with a high melting point. The emulsions obtained are then stable but exhibit cosmetic properties which are unacceptable to the user. This is because these compositions comprise very little water and therefore lack freshness when applied to the skin. In addition, they comprise a significant amount of humectants, such as glycerol, which leads to a feeling of stickiness to the touch. In addition, the use of a wax with a high melting point in an amount of 5% results in heavy textures which are very difficult to apply to the skin.
The need thus remains for an emulsion which has the appearance of a foam, while comprising a large amount of water, and which is fresh and not sticky when applied to the skin.